153 research outputs found

    Development and assessment of an antigen capture ELISA for the detection of epizootic haematopoietic necrosis virus (EHNV) in redfin perch (Perca fluviatilis) and rainbow trout (Salmo gairdneri)

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    Epizootic haematopoietic necrosis virus (EHNV) was grown in BF-2 cells, purified from cell culture material, and tested for cellular contamination by SDS-PAGE, western transfer and immunostaining with anti-BF-2 serum. Purified virus was introduced to sheep and rabbits to raise antiserum against EHNV. These antibodies were used in the development of an antigen capture enzyme linked immunosorbent assay (ELISA) for the detection of EHNV in redfin perch and rainbow trout. The ELISA format chosen after many optimisation experiments has the ability to detect virus in cell culture to a titre of 10\u27 TCIDst/ml. After screening 1,200 tissue homogenates by virus isolation and using the tissue homogenates and the culture supematants in an ELISA, positive/negative cutoffs of 0.95 and 0.75, respectively, were chosen. Although quite high these cutoffs did not affect the utility of the test. The sensitivity and specificity of the antigen capture ELISA appear more than adequate for diagnostic screening of test samples from fish populations

    Impact of Node Ablation on the Morphogenesis of the Body Axis and the Lateral Asymmetry of the Mouse Embryo during Early Organogenesis

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    AbstractThe node of the mouse gastrula is the major source of the progenitor cells of the notochord, the floor plate, and the gut endoderm. The node may also play a morphogenetic role since it can induce a partial body axis following heterotopic transplantation. The impact of losing these progenitor cells and the morphogenetic activity on the development of the body axes was studied by the ablation of the node at late gastrulation. In the ablated embryo, an apparently intact anterior–posterior body axis with morphologically normal head folds, neural tube, and primitive streak developed during early organogenesis. Cell fate analysis revealed that the loss of the node elicits de novo recruitment of neural ectoderm and somitic mesoderm from the surrounding germ-layer tissues. This leads to the restoration of the neural tube and the paraxial mesoderm. However, the body axis of the embryo was foreshortened and somite formation was retarded. Histological and gene expression studies reveal that in most of the node-ablated embryos, the notochord in the trunk was either absent or interrupted, and the floor plate was absent in the ventral region of the reconstituted neural tube. The loss of the node did not affect the differentiation of the gut endoderm or the formation of the mid- and hindgut. In the node-ablated embryo, expression of the Pitx2 gene in the lateral plate mesoderm was no longer restricted to the left side but was found on both sides of the body or was completely absent from the lateral plate mesoderm. Therefore, the loss of the node results in the failure to delineate the laterality of the body axis. The node and its derivatives therefore play a critical role in the patterning of the ventral neural tube and lateral body axis but not of the anterior–posterior axis during early organogenesis

    Stringent requirement of a proper level of canonical WNT signalling activity for head formation in mouse embryo

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    In mouse embryos, loss of Dickkopf-1 (DKK1) activity is associated with an ectopic activation of WNT signalling responses in the precursors of the craniofacial structures and leads to a complete truncation of the head at early organogenesis. Here, we show that ENU-induced mutations of genes coding for two WNT canonical pathway factors, the co-receptor LRP6 and the transcriptional co-activator β-catenin, also elicit an ectopic signalling response and result in loss of the rostral tissues of the forebrain. Compound mutant embryos harbouring combinations of mutant alleles of Lrp6, Ctnnb1 and Dkk1 recapitulate the partial to complete head truncation phenotype of individual homozygous mutants. The demonstration of a synergistic interaction of Dkk1, Lrp6 and Ctnnb1 provides compelling evidence supporting the concepts that (1) stringent regulation of the level of canonical WNT signalling is necessary for head formation, (2) activity of the canonical pathway is sufficient to account for the phenotypic effects of mutations in three different components of the signal cascade and (3) rostral parts of the brain and the head are differentially more sensitive to canonical WNT signalling and their development is contingent on negative modulation of WNT signalling activity

    dolls/puppets like mensch – dolls/puppets as artificial beings. Part 1.2

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    Die dritte Ausgabe der Zeitschrift denkste: puppe / just a bit of: doll (de:do), ein multi-disziplinäres Online-Journal für Mensch-Puppen-Diskurse, erscheint als Doppelheft, dessen gemeinsamer Themenschwerpunkt lautet: puppen/dolls like mensch – puppen als künstliche meschen. Mit diesem Fokus wird ein Thema aufgegriffen, das Menschen seit der Antike berührt und bis heute ihren Verstand und ihre Imagination, ihre Bedürfnisse und ihre Gefühle in Unruhe versetzt. In Mythologien, literarischen Fiktionen und Narrativen für Erwachsene und Kinder, in Werken der bildenden Künste, im Film, in mechanisch-technischen Anwendungen und Utopien, in den performativen Künsten, in der (Spiel-)Pädagogik und in den verschiedenen Bereichen der Popkultur wirft das Motiv der Puppe mit seinen unterschiedlichsten Ausdrucksformen immer auch existenzielle Fragen auf: Wer und was ist der Mensch? Die Puppe als künstlicher Mensch ist in gewisser Weise wie mensch, ohne Mensch zu sein. Als von Menschen geschaffene Abbilder, Vorbilder, Nachahmungen und Entwürfe des Menschen spiegeln und bestätigen Puppen vorhandene Lebenswelten und loten gleichzeitig Potenziale und Abgründe des Mensch-Seins zwischen Utopie und Dystopie, zwischen Neugier und Hingabe, zwischen Horror und Glückseligkeit, zwischen Macht und Ohnmacht aus. Puppen/dolls like mensch – der doppelte Wortsinn betont die gegebene Ambiguität der Puppen und die spannenden, ihnen innewohnenden Ambivalenzen. Im ersten Teilband (1.1) wird den Spuren und Erscheinungsformen des Puppenmotivs und der Puppe(n) – als literarisches Narrativ, als künstlerisches Motiv, als materialisiertes Objekt – vor allem im Kontext von bildender Kunst, Literatur, Fotografie, Theater und Androidentechnologien nachgegangen. Im zweiten Teilband (1.2) werden zum einen kinderliterarische und (spiel-)didaktische Texte akzentuiert, zum anderen sind hier verschiedene mediale und popkulturelle Formate aus den Bereichen Computerspiel, Comic-Film-Adaptation, Film (unterschiedlicher Genres) und dem Figurentheater versammelt sowie Thematisierungen der Verknüpfung von materiellen Artefakten und literarischen Narrativen. Rezensionen in Form von Essays über literarische Puppen-Narrative, eine Foto-Ausstellung und ein Ballett runden beide Ausgaben ab. Die zeitliche Spanne reicht vom Mittelalter bis in die Gegenwart und Zukunft und zeigt einmal mehr, wie über das Narrativ der Puppe uralte Menschheitsfragen in Traditionslinien eingebunden werden und sie auf faszinierende Weisen fortschreiben.The third edition of the journal denkste: puppe / just a bit of: doll (de: do), a multidisciplinary online journal for human-doll discourses, is a double issue whose shared thematic focus is: puppen/dolls like mensch – dolls/puppets as artificial beings. With this focus, we take up a topic that has concerned mankind since ancient times and has always upset their 'minds' and 'hearts’, their needs and feelings. In mythologies, literary fictions and narratives for adults as well as for children, in works of the visual arts, in film, in mechanical-technical applications and utopias, in the performative arts, in (play-)pedagogy and in the various fields of pop culture, the motif of the doll with its various forms of expression always raises existential questions: Who is man, what is human? The doll as an artificial human being is in a certain way like mensch without being human. As man-made images, as models, imitations and designs of humans, dolls/puppets reflect and confirm existing worlds and at the same time sound out the potentials and abysses of being human between utopia and dystopia, between curiosity and devotion, between horror and bliss, between power and powerlessness. Dolls/puppets like mensch – the double meaning of these words emphasizes the given ambiguity of the dolls/puppets and the intriguing ambivalences inherent in them. In the first part of volume (1.1) the traces and manifestations of the doll motif and of doll(s) – as literary narrative, as artistic motif, as materialized object – will be explored primarily in the context of the fine arts, of literature, photography, theater and android technologies. In the second part of the volume (1.2), on the one hand, children's literature and (play)didactic texts are accentuated; on the other hand, various media and pop-cultural formats from the fields of computer games, comic-film adaptations, films (of different genres) and puppet theater performances are gathered here, as well as issues that link material artifacts and literary narratives. Reviews in the form of essays on literary doll narratives, a photo exhibition and a ballet round off both editions. The time span extends from the Middle Ages to the present and future and shows once again how age-old questions regarding mankind and humanity are integrated into traditional lines and are carried on continuously in fascinating ways

    Effector-triggered defence against apoplastic fungal pathogens

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    Copyright 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license CC BY 3.0 (http://creativecommons.org/licenses/by/3.0/). hR gene-mediated host resistance against apoplastic fungal pathogens is not adequately explained by the terms pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) or effector-triggered immunity (ETI). Therefore, it is proposed that this type of resistance is termed ‘effector-triggered defence’ (ETD). Unlike PTI and ETI, ETD is mediated by R genes encoding cell surface-localised receptor-like proteins (RLPs) that engage the receptor-like kinase SOBIR1. In contrast to this extracellular recognition, ETI is initiated by intracellular detection of pathogen effectors. ETI is usually associated with fast, hypersensitive host cell death, whereas ETD often triggers host cell death only after an elapsed period of endophytic pathogen growth. In this opinion, we focus on ETD responses against foliar fungal pathogens of cropsPeer reviewe

    The Hitchhiker\u27s Guide to Europe: the infection dynamics of an ongoing Wolbachia invasion and mitochondrial selective sweep in Rhagoletis cerasi

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    Wolbachia is a maternally inherited and ubiquitous endosymbiont of insects. It can hijack host reproduction by manipulations such as cytoplasmic incompatibility (CI) to enhance vertical transmission. Horizontal transmission of Wolbachia can also result in the colonization of new mitochondrial lineages. In this study, we present a 15-year-long survey of Wolbachia in the cherry fruit fly Rhagoletis cerasi across Europe and the spatiotemporal distribution of two prevalent strains, wCer1 and wCer2, and associated mitochondrial haplotypes in Germany. Across most of Europe, populations consisted of either 100% singly (wCer1) infected individuals with haplotype HT1, or 100% doubly (wCer1&2) infected individuals with haplotype HT2, differentiated only by a single nucleotide polymorphism. In central Germany, singly infected populations were surrounded by transitional populations, consisting of both singly and doubly infected individuals, sandwiched between populations fixed for wCer1&2. Populations with fixed infection status showed perfect association of infection and mitochondria, suggesting a recent CI-driven selective sweep of wCer2 linked with HT2. Spatial analysis revealed a range expansion for wCer2 and a large transition zone in which wCer2 splashes appeared to coalesce into doubly infected populations. Unexpectedly, the transition zone contained a large proportion (22%) of wCer1&2 individuals with HT1, suggesting frequent intraspecific horizontal transmission. However, this horizontal transmission did not break the strict association between infection types and haplotypes in populations outside the transition zone, suggesting that this horizontally acquired Wolbachiainfection may be transient. Our study provides new insights into the rarely studied Wolbachia invasion dynamics in field populations

    Disease Severity, Fever, Age, and Sex Correlate With SARS-CoV-2 Neutralizing Antibody Responses

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    Clinical trials on the use of COVID-19 convalescent plasma remain inconclusive. While data on safety is increasingly available, evidence for efficacy is still sparse. Subgroup analyses hint to a dose-response relationship between convalescent plasma neutralizing antibody levels and mortality. In particular, patients with primary and secondary antibody deficiency might benefit from this approach. However, testing of neutralizing antibodies is limited to specialized biosafety level 3 laboratories and is a time- and labor-intense procedure. In this single center study of 206 COVID-19 convalescent patients, clinical data, results of commercially available ELISA testing of SARS-CoV-2 spike-IgG and -IgA, and levels of neutralizing antibodies, determined by plaque reduction neutralization testing (PRNT), were analyzed. At a medium time point of 58 days after symptom onset, only 12.6% of potential plasma donors showed high levels of neutralizing antibodies (PRNT50 >= 1:320). Multivariable proportional odds logistic regression analysis revealed need for hospitalization due to COVID-19 (odds ratio 6.87; p-value 0.0004) and fever (odds ratio 3.00; p-value 0.0001) as leading factors affecting levels of SARS-CoV-2 neutralizing antibody titers in convalescent plasma donors. Using penalized estimation, a predictive proportional odds logistic regression model including the most important variables hospitalization, fever, age, sex, and anosmia or dysgeusia was developed. The predictive discrimination for PRNT50 >= 1:320 was reasonably good with AUC: 0.86 (with 95% CI: 0.79-0.92). Combining clinical and ELISA-based pre-screening, assessment of neutralizing antibodies could be spared in 75% of potential donors with a maximal loss of 10% of true positives (PRNT50 >= 1:320)

    Portal hypertension in common variable immunodeficiency disorders – a single center analysis on clinical and immunological parameter in 196 patients

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    BackgroundLiver manifestations and in particular portal hypertension (PH) contribute significantly to morbidity and mortality of patients with common variable immunodeficiency disorders (CVID). Screening strategies and early detection are limited due to the lack of specific diagnostic tools.MethodsWe evaluated clinical, immunological, histological, and imaging parameters in CVID patients with clinical manifestation of portal hypertension (CVID+PH).ResultsPortal hypertension was present in 5.6% of CVID patients and was associated with high clinical burden and increased mortality (18%). Longitudinal data on clinical and immunological parameters in patients before and during clinically manifest portal hypertension revealed a growing splenomegaly and increasing gamma-glutamyl transferase (GGT) and soluble interleukin 2 receptor (SIL-2R) levels with decreasing platelets over time. While ultrasound of the liver failed to detect signs of portal hypertension in most affected patients, transient elastography was elevated in all patients. All CVID+PH patients had reduced naïve CD45RA+CD4+ T-cells (mean of 6,2%). The frequency of severe B-lymphocytopenia (Euroclass B-) was higher in CVID+PH patients. The main histological findings included lymphocytic infiltration, nodular regenerative hyperplasia-like changes (NRH-LC), and porto(-septal) fibrosis.ConclusionCVID patients with lower naïve CD45RA+CD4+ T-cells or severely reduced B-cells might be at higher risk for portal hypertension. The combination of biochemical (increasing sIL-2R, GGT, and decreasing platelets) and imaging parameters (increasing splenomegaly) should raise suspicion of the beginning of portal hypertension

    Cellular Adhesion Gene SELP Is Associated with Rheumatoid Arthritis and Displays Differential Allelic Expression.

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    In rheumatoid arthritis (RA), a key event is infiltration of inflammatory immune cells into the synovial lining, possibly aggravated by dysregulation of cellular adhesion molecules. Therefore, single nucleotide polymorphisms of 14 genes involved in cellular adhesion processes (CAST, ITGA4, ITGB1, ITGB2, PECAM1, PTEN, PTPN11, PTPRC, PXN, SELE, SELP, SRC, TYK2, and VCAM1) were analyzed for association with RA. Association analysis was performed consecutively in three European RA family sample groups (Nfamilies = 407). Additionally, we investigated differential allelic expression, a possible functional consequence of genetic variants. SELP (selectin P, CD62P) SNP-allele rs6136-T was associated with risk for RA in two RA family sample groups as well as in global analysis of all three groups (ptotal = 0.003). This allele was also expressed preferentially (p<10-6) with a two- fold average increase in regulated samples. Differential expression is supported by data from Genevar MuTHER (p1 = 0.004; p2 = 0.0177). Evidence for influence of rs6136 on transcription factor binding was also found in silico and in public datasets reporting in vitro data. In summary, we found SELP rs6136-T to be associated with RA and with increased expression of SELP mRNA. SELP is located on the surface of endothelial cells and crucial for recruitment, adhesion, and migration of inflammatory cells into the joint. Genetically determined increased SELP expression levels might thus be a novel additional risk factor for RA

    SARS-CoV-2 T Cell Response in Severe and Fatal COVID-19 in Primary Antibody Deficiency Patients Without Specific Humoral Immunity

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    Morbidity and mortality of COVID-19 is increased in patients with inborn errors of immunity (IEI). Age and comorbidities and also impaired type I interferon immunity were identified as relevant risk factors. In patients with primary antibody deficiency (PAD) and lack of specific humoral immune response to SARS-CoV-2, clinical disease outcome is very heterogeneous. Despite extensive clinical reports, underlying immunological mechanisms are poorly characterized and levels of T cellular and innate immunity in severe cases remain to be determined. In the present study, we report clinical and immunological findings of 5 PAD patients with severe and fatal COVID-19 and undetectable specific humoral immune response to SARS-CoV-2. Reactive T cells to SARS-CoV-2 spike (S) and nucleocapsid (NCAP) peptide pools were analyzed comparatively by flow cytometry in PAD patients, convalescents and naive healthy individuals. All examined PAD patients developed a robust T cell response. The presence of polyfunctional cytokine producing activated CD4(+) T cells indicates a memory-like phenotype. An analysis of innate immune response revealed elevated CD169 (SIGLEC1) expression on monocytes, a surrogate marker for type I interferon response, and presence of type I interferon autoantibodies was excluded. SARS-CoV-2 RNA was detectable in peripheral blood in three severe COVID-19 patients with PAD. Viral clearance in blood was observed after treatment with COVID-19 convalescent plasma/monoclonal antibody administration. However, prolonged mucosal viral shedding was observed in all patients (median 67 days) with maximum duration of 127 days. PAD patients without specific humoral SARS-CoV-2 immunity may suffer from severe or fatal COVID-19 despite robust T cell and normal innate immune response. Intensified monitoring for long persistence of SARS-CoV-2 viral shedding and (prophylactic) convalescent plasma/specific IgG as beneficial treatment option in severe cases with RNAemia should be considered in seronegative PAD patients
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